High pressure valve

ABSTRACT

A high pressure valve in which the valve needle is guided in a well formed in the valve body so that it can be moved to seat one end in a valve seat formed at the bottom of said well. Outlet and inlet passages communicate with the opposite sides of the seat whereby the flow of fluid between said passages can be controlled by axial movement of the valve needle. The valve needle is arranged and formed whereby the pressure of the fluid being controlled applies a retracting force to retract the valve needle. The valve needle drive means cooperates with said valve needle to overcome the retracting force and advance the needle into seating engagement in the valve seat.

[22] Filed:

United States Gordon atent 1 [54] HIGH PRESSURE VALVE [75] Inventor: Peter R. Gordon, Los Gatos, Calif.

[73] Assignee: The Board of Trustees of the Leland Stanford Junior University, Stanford, Calif.

Feb. 16,1971

21 Appl. No.: 115,607

[56] References Cited UNITED STATES PATENTS 9/1970 ..137/522 X 12/1944 ..137/509 X 11/1965 Henderson .....l37/625.68

6/1967 Hogg ..137/495 X 3/1969 Struck ..137/509 X Thomas et al. Edwards 1 May 15, 1973 FOREIGN PATENTS OR APPLICATIONS 111,493 6/1900 Germany ..137/509 Primary ExaminerMartin P. Schwadron Assistant ExaminerDavid R. Matthews AttorneyFlehr, Hohbach, Test, Albritton & Herbert [5 7] ABSTRACT A high pressure valve in which the valve needle is guided in a well formed in the valve body so that it can be moved to seat one end in a valve seat formed at the bottom of said well. Outlet and inlet passages communicate with the opposite sides of the seat whereby the flow of fluid between said passages can be controlled by axial movement of the valve needle. The valve needle is arranged and formed whereby the pressure of the fluid being controlled applies a retracting force to retract the valve needle. The valve needle drive means cooperates with said valve needle to overcome the retracting force and advance the needle into seating engagement in the valve seat.

5 Claims, 1 Drawing Figure PATH-HEB MAY. 5 I575 PETER R. GORDON IN V E NTOR BY m,

x iv M ATTORNEYS HIGH PRESSURE VALVE BACKGROUND OF THE INVENTION The invention described herein was made in the course of or under a grant from the National Science Foundation, an agency of the Government.

This invention relates generally to valves and more particularly to a self-retracting needle high pressure valve.

In the prior art, the valve needle is advanced and retracted by positive drive means. Because of backlash in the drive means, the valve cannot be smoothly retracted. The instant the valve is unseated, the high fluid pressures drive the needle outwardly until the backlash in the drive is taken up. In many high pressure applications, it is desirable to accurately and smoothly control the needle position. Prior art high pressure valves have been unsatisfactory in this regard OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide a V high pressure valve in which the valve needle position can be accurately controlled.

It is another object of the present invention to pro vide a high pressure valve having a self-retracting valve needle.

The foregoing and other objects of the invention are achieved by a valve in which a valve body is bored to form a well with the bottom of the well defining a valve seat. Inlet and outlet passages communicate with the bottom of said well from the opposite side of said seat. A valve needle is accommodated in said well and is movable between an advanced position where it is seated in the seat and a retracted position. The needle has one end formed of reduced diameter to provide a shoulder and thereby a space between the needle and the well at the bottom where by the passages can be placed in communication with one another. Packing means are carried at the end of said valve needle in abutting relationship with the shoulder whereby fluid under pressure in said space provides an axial retracting force to said needle to retract the needle. Drive means are adapted to abut the other end of the valve needle to overcome the axial retracting force to advance the needle towards its seated position.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE of Drawing is a cross-sectional view of a valve in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The valve includes a valve body lll including a threaded end 12. The valve body includes a well 13 adapted to receive the valve needle l4. Communicating with the well 13 is an enlarged bore 16 adapted to receive a thrust block 17. The bottom of the well 13 is provided with a valve seat 18 which cooperates with end 19 of valve needle 14 to control the flow of fluids from the inlet port 21 to the outlet port 22. The inlet and outlet ports communicate with the well E3 on opposite sides of the valve seat 18. The ends of the ports 21 and 22 are threaded as shown at 23 and 24 to receive associated fluid conduits.

The valve needle 14 includes a portion Mia and portion 14b of reduced diameter with its end conically shaped 19 to seat in seat 18. The transition between the portions Ma and 14b includes an inclined surface 26. Packing means 27 are carried on the portion 14b and are adapted to abut the inclined surface 26. The packing means 27 may comprise brass ring 27a, lead ring 2%, leather ring 270 and an- O-rin g 27d. The rings serve to form a seal between the needle and the walls of the well 13 whereby fluid pressures in the space 28 act on the packing 27 to generate axial retracting forces to retract the valve needle from its seated position. Thus, there is a force urging the needle towards its retracted position. Any fluid which escapes past the packing means flows into the space 29 which is vented to the atmosphere by passage 30.

The outer end of the valve needle abuts the thrust block 17. The threaded portion of the valve body 12 threadably receives fulcrum body 31. The fulcrum body 31 accommodates a thrust piston 32 which extends through the opening 33 formed in the fulcrum body. The end of the piston includes a groove 34 which receives dowel pins 35 and 36 carried by bell crank levers 37. The bell crank levers are pivoted on pins 38 and 39 carried by the fulcrum body 31. The ends of bell crank lever 37a receive a threaded clevis 41 and the lever 37b, and unthreaded clevis 42, both of which cooperate with the screw 43 which carries stop 44. By rotating the screw 43, the bell crank levers are caused to pivot about pins 38 and 39 in opposite directions to move the thrust piston 32 inwardly forcing the thrust block and valve needle inwardly into a seated position or outwardly to allow the needle valve to move outwardly under the pressure created by the fluid within the chamber 28 to unseat the needle. It is to be observed that at all times forces are generated which urge the valve needle outwardly and maintain all parts under pressure whereby movement or rotation of the screw 33 will either allow the needle to move further outwardly or will force the same inwardly without backlash.

It is to be understood that the drive means for the piston 32 can include other drive means. The means illustrated and described were found to be preferably under the high pressure conditions to which one valve was subjected, namely, fluids under pressure between 30,000 and 150,000 psi. Furthermore, by the use of the lever arrangement shown, it is possible to obtain very small amounts of movement with each turn of the screw 43. it is further to be observed that the bore 16 is of larger diameter than the opening 33 and likewise that the thrust block, when it moves outwardly a predetermined distance, will abut the fulcrum body 31. Under extremely high pressures to which the valve is subjected, this is a safety measure preventing any injury to personnel in the event that the thrust piston is removed or the drive fails. At most, the valve needle will retract a distance corresponding to the distance between the back of the thrust block 17 and the fulcrum body 311.

Thus, it is seen that there has been provided a high pressure valve in which the effects of backlash are overcome by employing a self-retracting valve needle.

ll claim:

ll. A valve comprising a valve body, a well formed in said body with a valve seat formed at the bottom of said well, inlet and outlet pressure passages communicating with said well from opposite sides of said valve seat, a valve needle accommodated in said well and movable between an advanced seated position and a retracted position, said valve needle having one end of reduced diameter to form a shoulder along the needle and provide a space between the needle and well at said one end whereby the pressure passages can be placed in communication with one another, packing means carried by said end of said needle in abutting relationship with said shoulder whereby fluids under pressure in said space provide a continuous axial force on said packing and needle to retract the valve needle, and unyielding drive means adapted to abut the other end of said needle to overcome the axial retracting forces to advance the needle towards its seated position.

from said needle. 

1. A valve comprising a valve body, a well formed in said body with a valve seat formed at the bottom of said well, inlet and outlet pressure passages communicating with said well from opposite sides of said valve seat, a valve needle accommodated in said well and movable between an advanced seated position and a retracted position, said valve needle having one end of reduced diameter to form a shoulder along the needle and provide a space between the needle and well at said one end whereby the pressure passages can be placed in communication with one another, packing means carried by said end of said needle in abutting relationship with said shoulder whereby fluids under pressure in said space provide a continuous axial force on said packing and needle to retract the valve needle, and unyielding drive means adapted to abut the other end of said needle to overcome the axial retracting forces to advance the needle towards its seated position.
 2. A valve as in claim 1 wherein said shoulder is inclined to urge the packing outwardly against the walls of the well.
 3. A valve as in claim 1 wherein said packing is retained by means of an O-ring.
 4. A valve as in claim 1 wherein said drive means includes a thrust block carried in said body for transmitting forces between the needle and associated drive.
 5. A valve as in claim 4 including means limiting movement of said thrust block under retracting forces from said needle. 